US 2669360 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
1954 J. w. LITTLE ADJUSTABLE FILTER SCRAPER BLADE Filed Nov. 29, 1951 INVENTOR. JOHN W Ll TTLE Patented Feb. 16, 1954 ADJUSTABLE FILTER SCRAPER BLADE John W. Little, Birmingham,
Ala., assignor to Goslin-Birmingham Manufacturing Company, Inc., a corporation of Alabama Application November 29, 1951, Serial No. 258,836
This invention relates to an adjustable scraper blade for rotary filters and has for its principal object the provision of such a blade which shall be easily adjusted to the exact pressure required from the outside of the casing and while the filter is in operation.
Another object of my invention is to provide an adjustable scraper blade of the character designated which may be easily adjusted to cause the blade to bear against the surface of the filter drum sufficiently to remove the cake formed thereon and yet not bear hard enough to damage the filter cloth.
A more specific object of my invention is to provide an adjustable filter scraper blade which is especially adapted for use on filters employed in the solvent de-waxing of oil.
A still further object of my invention is to provide an adjustable filter scraper blade which shall be easily adjusted to bear against the surface of the filter drum with substantially uniform pressure from end to end by a single operation, thus eliminating the necessity of having to make several adjustments longitudinally of the blade every time the blade is adjusted.
Heretofore in the art to which my invention relates, the scraper blades have been adjusted on the drum by stopping the operation of the filter and, with a closed type filter removing the outer casing. The blade was then adjusted, by whatever means available, to what would appear to be the proper pressure. The casing was then closed and the filter put back in operation. Such an adjustment of the scraper blade has been un satisfactory not only because it has entailed a shutting down of the filter in order to carry it out, but also it is very difficult to adjust the blade to the proper pressure while the filter is not in operation.
Also, when the filter is being used with propane or other volatile solvents it is necessary to stop operation of the filter, open it up and steam it out for several hours before one can get inside to adjust the blade.
It is very important in the operation of rotary filters that the flexible scraper blade bear against the surface of the filter drum with just sufficient pressure to remove the cake formed thereon. If the blade bears too hard against the surface, the wires which hold the cloth in place on the drum will Wear the scraping edge of the blade, causing sharp edges which cut or damage the cloth.
An adjustable filter scraper blade embodying features of my invention is illustrated in the accompanying drawings forming a part of this application, in which: r
Fig. l is a fragmentary front view, partly in section, taken along the line I-I of Fig. 2;
Fig. 2 is a view taken along line II--II of Fig. 1;
Fig. 3 is a view taken generally along the line III-III of Fig. 1;
Fig. 4 is a detail view IV-IV of Fig. 3; and
Fig. 5 is a detail view taken along the line V-V of Fig. 1.
Referring now to the drawings for a better understanding of my invention I show a fragment of a rotary filter embodying a closed casing Hi and a cylindrical drum II which may be provided with any suitable filtering medium, such as cloth I? held in place by wires 13 wound spirally about the drum. Also, the drum is provided with the usual partition walls I4 forming a plurality of compartments.
The casing H] is provided with end Walls I5 and I8 and extending between and secured to the end walls as by welding at I! is a vertically extending partition wall I8 which is spaced from the drum II, as shown in Fig. 2. Secured to the lower end of the wall l8 and to the inner wall oi the casing I0 is a trough I 9 having rotatably mounted therein a screw conveyor 2| for removing the material scraped from the drum ll.
Mounted on the wall [3 by any suitable means and extending substantially the length of the drum II, is an upwardly tapered bar 22. Secured to the bar 2?. by means of bolts 24 is a plate 26 which also extends substantially the length of the drum I I. While I show the bar 22 and the plate 26 as being separate, they may, if desired, be formed integrally.
Pivotally mounted at the top of the plate 25 by a hinge connection 27 is a scrap-er blade 28 which may be divided transverselyas at 25 to form a plurality of sections 28' which may be individually adjusted with respect to each other. The over all length of the blade 28 is slightly greater than the length of the drum H. The hinge connection 2? comprises spaced sleeve members 23 and 3! which are secured to the top of the plate 26 as by welding or other suitable means. Secured to the underside of the blade 23 and fitting between the spaced sleeve members 29 35 is a hinge member 3-3 which has a sleeve portion at fitting between the sleeves 29 and 35. Extending through the sleeves 29, 34 and 3! is a hinge pin 36, about which the scraper blade 2% thus free to rock.
Mounted on the underside of the blade 28 by any suitable means such as screws 3'! are a plurality of leaf springs 38. The leaf springs are spaced longitudinally along the scraper 218 at taken along the line 4| extends outwardly of the outer casing [01 through a stufiing box $2 in the end Wall I6. The stufiing box 42 is provided with a suitablepacking gland 43 to prevent leakage. outside of the casing 10. Adjustably mounted onthe. shaft M,
by any suitable means such as set screws 40,.op--
posite each of the leaf springs 38 is a crank arm. 44. Pivotally mounted at the free'end" of" each crank arm 44 is a push rod 46.
Mounted at the outer "end of each push rod 46 is ashort piece ofrod A! which extends parallel to theshaft 4|. Each rod 41 is disposed between its associated leaf spring 33v and the plate 26, whereby upon upward movement thereof the leaf spring 38 and the bottom of the. blade28 are urged. away from the plate 2.6. and the scraping edge of the blade is urged. towardthedrum H.
The outwardly projecting end of the shaft M is squared as at 4-3 and is provided with anopeningAB for receiving. a suitable tool for turning it.
Keyed to the shaft M outwardly of the outercasing Hlis abracket 5! having a quadrant slot 52 therein. Mounted on the outer wall of the casing. iii-adjacent the shaft 4| is anoutwardly projectin arm 53"having a downwardly extending portion 54 adjacent the bracket 56, as shown in Fig. 1. The downwardly extending portion-.54 is "provided with an internally threaded open-.- ing56 opposite the s1ot52, for receiving. a screw 57.. The screw til passes through the slot 52 and into the opening 55 thus providing. means for. locking the shaft and blade assembly at any desired position.
Fromthe foregoing. description, the. operation of my adjustable-filterv scraper blade will bereadily understood. When the blade isinstalled an initial. adjustment may be necessary. This ad-- I justment ismade. by loosening the set screws and adjusting the individual crank arms 44 so asto position the. entire scraping. edge of all-.the sections 28' of the blade against the drumv l I.
This. initial adjustment of the'bladeais veryim portant for. the reason thatthe surfaceof long drums and the scraping edges of the-blades therexfor are generally uneven, thus causing. uneven pressure, of the blade against thedrumz. By adjusting. the individual crank arms, all points along the entire length of the-blade-- bear with substantially the same pressure against the drum.
Filtersof the classhaving a closedcasing are usuallyprovided with peep holes 58 having pressure. tight glass covers 59 whereby'the-operation ofithe: filter may be observed from the outside. m making-the final adjustment of the blade, the
operatorlooks through one of the peep holes 58" in'the. casingand turns the-shaft 4| bya suit able tool at 48 or M3, as the case maybe, so as to cause the rods 45! to move downwardly toward: the lower end of the spring 38' thereby causingallsections 28 of the blade to be slacked off between. the leaf springsiiB and; the. plate 26. thus:
forcing the lower end of the leaf spring outwardly and causing the scraping edge of the blade 28 to bear against the drum ll with suflicient pressure to remove the cake. The blade and shaft 4! are then looked in the adjusted positiomby; tightenin the screwfii.
While I have shown my. invention in" but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore; that onlw such limitations shall be placedathereuponzaas are specifically set forth in thezappended-claims.
What Lclaim is:
1; The combination with a rotary filter embodyingza'. cylindrical filter drum and a closed casing therefor, together with a scraper blade piyotally. mounted! tobear. against said drum, ofZ'an-upwardly tapered;p1atev mounted inwardly of! said. blade,; aplurality, of: spaced: apart; lea-f. spring, memberseach. being; secured at oneend to theblade: along, the entire length. thereof',.the free ends of said spring members; extending in a direction awayfrom the: scraping edgezofrsaid blade intermediate the'blade and said plate, a movable member for eaohspring member'inzposietion to slidably engage between. the free-,endaof its. associated springmember: and said platevand urgexthe scraping edge of. said. blade toward. said drum, a shaft extending through one? endiof: said. closed: casing. and operatively: connected. to each. of: said movable: members: for. moving the same, and means outwardly; of: said" casing: for; rotating said shaft."
2. Thecornbinationiv set:- forth; in? claimalin which the means for locking:theshafttiniselecteed positions comprisesa bracket rigidly secured to.-the shaft I outwardly of: the: closed: casing; a bracket secured to": thefouter. wall; of. said: casing adjacent. saidv first mentioned bracket" amine".-
' leasabla means: locking; said; brackets to: each other in selected-positions;
3: In a rotary drum filter-havingga -pivoted scraper. blade-,1 a; plurality-- of' leaf springs: dis:- posed. at intervalsunderneathqther blade and: along the-length thereof, each. ofi said? springs having'one'end' securedato the underside of: the blade and. the-other; extendingfreely at: aniangle. away from the blade; means-for adjusting. the: tension of. said springs: andthereby, thetpressureofv the. blade againstthe. drum: comprising-2am upwardly extendin member mounted, inwardly: of saidspringaa shaft: extending alongsiderthe". drum longitudinallyfi'thereof; crankarmson the shaft, means fort-adjusting; the. individual crank; arms on the shaft thereby causingvtheyentires blade to bearwith substantially uniform. pressureagainst the drum; and push. rods; connected to. the crank. arms: with the-free ends: thereof slidably fittin between: said: upwardly extending, member and said springs.
4;.An adjustable scraper: for a: rotary. filter drum comprising an x upwardly eXtendingimem,- ber mounted:adjacent saidadrum; a scrapenblade pivotally mounted adjacent the toner said'smemiher and adapted? to bear" against: said .drum,. a: plurality of" spacedaapartl flexible; members seecured to the blade alongthexlengthithereofanw having; their free ends extendingin a: direction: away from the scrapinged-ge of: said blade in" termediatessaid'bladeandsai'd'upwardly extend ing; member, a shaft rotatably mounted adjae cently below said upwardl'yr extendingmemher and extending parallel to said drum, crank arms adjustably mounted on said shaft opposite each of said flexible members, push rods pivotally mounted to said crank arms with the free ends of each slidably fitting between its associated flexible member and said upwardly extending member and urging the scraping edge of said blade toward and away from said drum upon rotation of said shaft in opposite directions.
5. The combination with a rotary filter drum having a scraper blade divided transversely into a plurality of sections and pivotally mounted to bear against said drum, of an upwardly extending member mounted inwardly of said blade, a plurality of spaced apart flexible members disposed at intervals along the blade, each being secured at one end to the blade and with a free end extending away from the scraping edge of the blade intermediate the blade and said upwardly extending member, and a movable mem her for each flexible member in position to slidably engage between the free end of its associated flexible member and said upwardly extending member and urge the scraping edge of said blade toward said drum.
JOHN W. LITTLE.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,415,859 Bates May 16, 1922 FOREIGN PATENTS Number Country Date 176,619 Great Britain Mar. 16", 1922